To me it seems like you need a way to channel your anger. Take a look at this link:
teenhut.net/depression-self-ha…ternatives-self-harm.html
I know it says alternatives for self harm, but there's a category for things to do when you feel angry. I use it a lot, when I feel like I want to hit someone, or fight someone, and it can be very helpful. So take a look at that the next time you feel the need to fight with your brother.

Now, have you talked to your brother about respecting you and your things? Have you spoken to your mother about how he treats you?
These are some things you might want to consider. When you're calm, write down all the things you want to say to him, and explain to him what you'd prefer he not do (wear your clothes, open your mail, ect). Then read it to him. I recommend that you write it first and then read it so that you have your thoughts right there on paper for you to see, so you know what you want to say.

have you pointed that out to your mom?

my mom does the same thing
for me it never stopped so I eventually learned to accept it and therefore it didn't piss me off so much
what we cannot stand we must fight, what we cannot fight we must endure

I see where u coming from with your brother being disrespectful to you. What helped me get over that, was asking myself, why I feel the need 2 be respected by him..coz surely if I respect myself it should be enough. I can see you're a tough person and you don't need anyone to control how you feel by being a douche2u, Im sure you respect yourself enough to not allow that to happen -getting upset & fighting with him is like letting him win. Keep on keeping man

Move out the house, can't believe your mum even lets you stay in the house after hitting her. GO live on your own. It's best for everyone, your a threat to every one in the house hold.

meet a counselor to counsel ur family problems

Don't kill yourself! I've been through this and yes, I still do think about killing myself, but I think of the other stuff that I'll have to leave behind; all my friends and everything I wanted to do when I was of age. You have so much to live for...forget your brother, stand tall and forget him. And I can't believe your mom goes against you...I'm sorry for that

life is just that; something you must live with. It's a struggle everyday. It's fight til the finish. It's a game of being serious.

You are stronger than your emotions. Just as you are able to feel insecure, angry, and sad you can feel acceptance, understanding, and contentment. Anger is not a base emotion. It comes from pain and fear. So you have to go to the root of the problem and fix it. In the end, the one responsible and the one in control is you. At the end of your life, you're gonna have to look back and lay claim on every memory- so make as many good ones as you can.

I'm not trying to be rude when I say this, but to help your situation, you must first help yourself and get rid of all excuses.

I wish you the best of luck.

haha i see. You're powerful aren't you?

let me ask you; Do you like physical combat? do you love battle?

It sounds like a lot of this violence is coming from you, not your surroundings. That's what I got from your anecdote, anyway. You have to admit you may have been overreacting to your brother's actions; siblings borrow/snoop around in each others stuff all the time. It seems like life will get a lot easier if you can learn how to express your anger in a calm, articulate fashion. There are many ways to do this, but you should probably do something about your explosive nature quickly before you hurt someone you love even more. Try what has been suggested: looking at the alternatives to self harm page and/or talking it over with a counselor. Do this and you'll find yourself thinking clearly enough not to commit suicide.

You need counseling or anger management or some shit. You don't ever hit your mom and don't sit there feeling sorry for yourself either.